当字符串是使用 MySQL 的表中另一列中的数据时，如何在表的一列中搜索字符串

Question

I have one table that contains knowledge article information in our knowledge base.

For simplicity, it contains the following columns:

articleID, title, knowledge_base, state, article_content

The state is the workflow state of the article, of which I only care about the published version and article content is the html for the articles.

We are removing knowledge_base2, but there are articles in knowledge_base1 that link to those articles and I need to find and remove those links.

The links contain the articleID of the article, so I thought this would be easy.

I want to search the article_content column for any reference to the articleIDs of knowledge_base2. I used this code:

/* Any knowledge_base1 articles that link to an article in knowledge_base2. */
Select a.articleID, a.title
FROM table1 a
Join (SELECT articleID 
    From table1 b
    Where state = 'Published' 
    AND knowledge_base LIKE 'Knowledge_base2') b
ON a.articleID = b.articleID
WHERE a.knowledge_base = 'Knowledge_base1'
AND a.state = 'Published'
AND a.`article_content` LIKE concat('%',b.articleID,'%')
ORDER BY a.articleID

When I run this I get no results but no errors. I know there are links in Knowledge_base1that reference those article IDs in Knowledge_base2 so there should be plenty of results. I assume this line is where I am wrong: "AND a. article_content LIKE concat('%',b.number,'%')" Is there a better way to write this? Note, I have read only permissions to this database, and am not able to use local temp tables.

Answer 1

An example of the data in the table would look like this:

| articleID |         title          | knowledge_base  |   state   |       article_content                   |
+-----------+------------------------+-----------------+-----------+-------------
| KB0001    | How to fix a widget    | knowledge_base1 | Published | http://sp?id=kb_article_view&sysparm_article=KB0002 |
| KB0002    | How to make a sandwich | knowledge_base2 | Published | Random HTML content                                 |
| KB0003    | How to buy a car       | knowledge_base1 | outdated  | http://sp?id=kb_article_view&sysparm_article=KB0004 |
| KB0004    | House FAQs             | knowledge_base2 | Published | Random HTML content                                 |
+-----------+------------------------+-----------------+-----------+-------------

Final comment: After much more research and testing This was what I found that appeared to give me the answer I needed:

Select a.articleID, a.title
FROM table1 a
Join (SELECT articleID 
    From table1 b
    WHERE knowledge_base LIKE 'Knowledge_base2') b
ON a.article_content LIKE concat('%',b.articleID,'%')
WHERE a.knowledge_base = 'Knowledge_base1'
AND a.state = 'Published' 
ORDER BY a.articleID